DTSTTCPW – What does it mean?

“Do The Simplest Thing That Can Possibly Work” – that’s what. Now, what does that mean?

The actual expression comes out of the XP camp. Supposedly it was originally a reminder to ask what is the simplest thing that could be done, but I actually prefer the active version.

I’ve been asked questions like this recently at work, and thought I’d take a moment out to write up my thoughts. That’s what this is for, after all… me. 🙂

Let’s break the statement down into component parts, shall we?

Do
This one is easy: you have to do it. Talking about it won’t help. Drawing up pretty pictures won’t help. Anything that isn’t actually doing the solution won’t help.

Simplest
A good way to break this down is to invert it. What’s the opposite of simplicity? Complexity. Thus, asking us to do the simplest thing is to ask us to do the least complex thing. This is good; software is already complex, and natural complexities will creep in without us adding unnecessary complexity into the picture. Adding unnecessary complexity has a very good description: over-engineering. Over-engineering is wasteful. Note that reducing complexity is hard; asking someone to produce the simplest design is to ask them to spend a lot of effort coming up with a better way.

Work
This is the caveat clause. A lot of detractors of this statement focus on the “simplest” statement and invent ridiculous strawman arguments. This clause demolishes them. If the solution doesn’t “work”, then it doesn’t meet the necessary conditions. If it does work, you don’t need to complicate it any further, do you? My personal definition of “work” is “passes all the tests”; this naturally puts the burden of proof onto testcases.

So, to rephrase this: DTSTTCPW asks us to use the least complicated solution that actually solves the problem at hand. Put it like this, it makes a lot of intrinsic sense.

Also: remember that XP is a “holistic” process. Slogans are like sound-bites: they are usually taken out of context. DTSTTCPW requires a lot of enablers, which a full XP process “just happens” to put into place. Above all, you need the ability to put in a more complex solution should the simplest thing turn out to not work after all.

Author: Robert Watkins

My name is Robert Watkins. I am a software developer and have been for over 20 years now. I currently work for people, but my opinions here are in no way endorsed by them (which is cool; their opinions aren’t endorsed by me either). My main professional interests are in Java development, using Agile methods, with a historical focus on building web based applications. I’m also a Mac-fan and love my iPhone, which I’m currently learning how to code for. I live and work in Brisbane, Australia, but I grew up in the Northern Territory, and still find Brisbane too cold (after 22 years here). I’m married, with two children and one cat. My politics are socialist in tendency, my religious affiliation is atheist (aka “none of the above”), my attitude is condescending and my moral standing is lying down. View all posts by Robert Watkins